Now... I've read hundreds of yaoi manga... but this one is probably in my Top 3 favorites list. The art may not be everybody's taste (I was put off at first too), but the story makes up for it big time and you'll get to like it ( had same experience with Yamada Yugi).
Main Characters:
Chiga may be your usual popular, vain seme, but his big heart and sometimes sadistic streak (initiating the smut) makes him a very sympathetic guy.
Kokusai. I love him. He seems like a dull and naive uke, but this changes once he gets a taste of smexing with Chiga.
Which means he'll become permanently horny.
And how he copes with that change is simply hilarious.
Storytelling:
I'd even call this a comedy. The awkward situations in which the characters unwillingly get themselves into and desperately try to get out of, their way of speaking, silly metaphors... Kaori Monchi is an expert in these fields.
Another thing is the flow of the events. Every change of expressions and thoughts is captured, which adds to the impact of whats going on. And god... the smut scenes... ~10 pages for a masturbation scene ...an average of 30-40 pages for a sex scene... is there a similiar manga like this out there? i can't think of one...
Anime: It's awesome, but it does not really live up to the manga. I think it's a bit too fast paced and some things are left out, but that's normal for an anime based on a manga...
Info: I've read the german version up to vol.4. It says "to be continued in Vol 5" and the afterword implied the same, so I changed the info of this page...
And lastly: BUY IT! you definitively won't regret it.